Furnace for sintering, calcining, roasting, and smoldering of substances and process for working said furnace



NOV. 17, 1931. c, LQESCHE 1,832,226 FURNACE FOR SINTERING, CALCINING,ROASTING, AND SMOLDERING OF SUBSTANCES AND PROCESS FOR WORKING SAIDFURNACE Filed Oct. 10, 1928 2 Sheets-Sheet 1 In vemar';

fen/s7 C. Lassa/l5 Nov. 17, 1931. E. c. LOESCHE 1,832,226 FURNACE FORSINTERING, CALCINING, ROASTING, AND SMOLDERING 0F SUBSTANCES AND PROCESSFOR WORKING SAID FURNACE Filed Oct. 10, 1928 2 Sheets-Sheet 2 In van/0r:EBA/.3 T C Lassa/46 WWMAW Patented Nov. 17, 1931 'nmvsr over LorisorrE,on IBERLIN-LANKWITZ, GERMANY rUmvAon non smrname, CALCINING, aoas'rme,AND SMOLDERING or SUBSTANCES AND raooEss ronwonxnve'sam FURNACEApplication filed October 10, 1928, Serial No.

The inventionrelates to chamber-furnaces in which all particles ofmaterial to becalcined are, if possible in continuous working, passingthe flame, or zone kept at the required temperature, directly on theirway to the furnace, in order to be discharged thereafter, possiblyautomatically from the furnace. A chamber is for this purposeused, atthe one end of which the flame enters preferably from above, beingpractically producedby means of oil, gas, coal-dustete, while thematerial to be calcined enters at the oposite side in such a way, thatthematerial to be .calcined opposes the flame about in the shape of acrater-like heap. Thecalcined' particles of material are forced over theedge, while the material following-is coming up from the inside of thesaid heap.

The advantage of the invention consists .20 therein, that the flame onlystrikes fresh particles to be calcined and consequcntlycan not destroythe walls of the chamber. As the supply of the material to be calcinedcan be adjusted exactly corresponding to the 'com- 2 bustion and theflame can likewise very easily be regulated, every single particle ofmaterial to be calcined will be calcined thoroughly, without having toremain longer in the furnace than necessary. g

The consequence is, that thefurnace will in itself be of comparativelysmall dimensions and can be made very cheaply."

. Several constructions of a chamber-furnace according to the presentinventionhave been illustrated'by way of example in the accompanyingdrawings, in which:

7 Figs; 1+3 show diagrammatically 8 different constructions, of thefurnace in vertical section, v v

Fig. 4 shows another modified construction in vertical section.

In Fig. 1 the calcining-chamber is marked 1, having a raised bottom 2,with a central elevation or hearth 2, walls 3, and aceiling 1. Avertical canal 5 has been provided inthe 311,667, and in Germany October14, 1927..

bottom 2, through which the material to be treated is conveyed to the,furnace. The canal 5 discharges to the upper surface of the hearth 2'.

A pipe 6 hasbeen passed through the ceiling 40f themfurnace, locatedopposite the canal 5, This pipe Gserves for supplying the fuel. The pipe6 is surrounded by a pipe 7,

through which air is admitted. The two pipes 8. and 9, connected toopenings in the side-walls 3, serve for the outlet of the flue-gases.The flaps 10 and 11, provided on the side-walls 8, serveforclosingopenings through which the ready calcined material can be.removed, after the fiapslO and 11 have been opened. e

- In the construction according to Fig. 2, 1 -6and10 and 11dcsignate'thesame parts as in Fig. '1. The air is supplied by. two

pipes.1 2,and,l3 provided in the ceiling Lofthe furnace. The dischargeof the flue-gases is effected through the pipes 14 and 15,likewisearranged in the ceiling 4. l Inside of the furnace-chamber 1,two annular receptacles 16, 17 have been provided, for water andconnected with one another by vertical pipes 18, 19; A steam-boiler isproducedin this way, by which the heatof the furnace-chamber isutilized. The produced steam can escape by the pipe 16.

The construction according to Fig. 3 differs from the constructionaccording to Fig. 1 only thereby, that an annular canal 20 has beenprovided in the bottom 2, being connected with'ring-like gaps21. Part ofthe combustion-air is supplied to the furnacechamber by way of theannular space and the g p y In the construction according to Fig. 4, thefurnace-chamber 1 is provided with a bottom 2, side walls 3,and aceiling l. 6 is a pipe for supplying the fuel, 7 a pipe for the supplyof air. Adjustableopenings 7 have furthermorebeen rovided in the ceiling4, forthe supply of additional air.

In the side-Walls 3, several outlet-openings 22 have been providedentering an annular canal 23, connected with a smoke-flue 24.

In the hearth 2, a canal 5 has been provided for feeding the material tobe treated. The canal 5 discharges to the upper surface in of the hearth2. The material is supplied for'the feed-water, and a discharge-pipe forthe produced steam.

The bottom 2 of the furnace-chamber has a cylindrical elevation 2projecting from an inclined surface 36. At the lower end of thisinclined surface 36 adischarge-opening has been provided, usually heldclosed by the flap 37. The flap 37 is loaded by a 7 Weight 38. Above theflap 37 a pipe 39 has been provided, through which cold air can beadmitted for the purpose of cooling the heated material.

' The working method of the furnace is the following:

The material to be calcined is, according to the construction explainedin Fig. 4C, supplied to the bottom of the furnace through the canal 5 bymeans of the worm 28, and the piston 25, forming there a crater-likeheap 40. As soon as a sufficiently high enough heap has been formed, thefire is turned on. The flame escaping from the pipe 6 is directed uponthe point of the cone 40. As fresh material is supplied through thecanal 5, the

material treated by the flame rolls down over the mantle-surfaces of thecone upon the inclined surface 36 and in this way to the discharge flap37. The brickwork cannot be damaged by the flame, as the flame onlystrikes the heap of material 40. The heat produced in thefurnace-chamber is utilized in the boiler 33, for the production ofsteam. The air, supplied through the pipe 39, is warmed by theready-treated material and serves for the combustion of the fuelsupplied by means of the pipe 6. F or treating some suesgxtnces,indirect heating can be employed, d in this case, the supply and thepath (f the material to be calcined is so regulated, that every particlewhich movesthrough the zone of combustion, has the required temperature.

According to the shape of the surface of the chamber-bottom 2 the heapof material 40 can be giventhe form of a more or less high tone, apyramid or the formof a saddle. In some cases it may be practical toarrange the axis of the cone and the arms of the pipe 6 at an angle toeach other.

I claim:

1. In a furnace, an open horizontal hearth adapted to receive thematerial to be treated, a canal in said hearth for the supply of saidmaterial to said hearth, said canal discharging to the upper surface ofsaid hearth so that it'is covered by the material supplied to saidsurface, a burner above thedischarge opening of said canal, the flame ofsaid burner being directed upon the material.

2. In a furnace, an inclined bottom, side Walls surrounding the bottom,a ceiling supported by: the side walls, an open horizontal hearthprojecting from said bottom and adapted to receive the material to betreated, the side wallat the lower end of said inclined bottom having adischarge opening, a canal in said hearth for the supply of saidmaterialto said hearth, said canal discharging to the upper surface ofsaid hearth so that it is covered by the material supplied to saidsurface, a burnerabove the discharge opening of said'canal, the flame ofsaid burner being directed upon the material.

3. In a furnace, an inclined bottom, side walls surrounding the bottom,a ceiling supported by said side walls, an open horizontal hearthprojecting from the bottom adapted to receive the materiahto be treated,a canal in saidhearth for the supply of said material to said hearth,said canal discharging to the upper'surface of said hearth so thatit iscovered by the material supplied to said surface, a burner in saidceiling above the discharge opening of said canal, the flame of saidburner being directed upon the material,-a circular receptacle for Waterin said combustion chamber, said receptacle surrounding the burner, asupply pipe for water and a discharge pipe for steam'arranged on saidreceptacle.

' 4. In a furnace, an inclined bottom, side walls surrounding thebottom, a ceiling supported by said side walls, an open horizontalhearth projecting from said bottom and adapted to receive the materialto be treated,

the side wall at the lower end of said inclined bottom having adischarge opening therein, a canal in said hearth for the supply of saidmaterial. to said hearth, said canal discharging to the upper surface ofsaid hearth so that it'is covered by the material supplied to saidsurface, a burner in said ceiling above the mouth of said canal, theflame of said burner being directed upon the material, a

canal for the supply of air in that sidewall,

which contains the discharge opening, the last-mentioned canaldischarging near to said discharge opening so that the air passes theheated materialr o 5. A process for working furnaces, consisting inforcing the material to betreated nature.

ERNST CURT LOESCHE.

